Facilitating audio playback during display sleep mode

ABSTRACT

The disclosed embodiments relate to a system for managing power for a display. During operation, the system receives a video-blank command, which specifies that the display is to enter a video-blank mode wherein the display outputs a blank screen. In response to the video-blank command, the system causes the display to output a blank screen, and powers down display components associated with outputting a display signal to the display. In some embodiments, the display additionally comprises audio components including an audio-output device, and powering down the display components involves maintaining an existing power state for the audio components, so that the audio components can continue to output an audio signal while the display components are powered down.

RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 to U.S. Provisional Patent Application No. 61/368,164 filed 27 Jul. 2010, entitled “Using a Display Abstraction to Control a Display” by the same inventors as the instant application (Attorney Docket No. APL-P9058USP1). The subject matter of this application is also related to the subject matter in a co-pending non-provisional application by Maciej Maciesowicz and David A. Curran, Ser. No. 12/850,123, filed on 4 Aug. 2010 application entitled, “Using a Display Abstraction to Control a Display” (Attorney Docket No. APL-P9058US1

BACKGROUND

1. Field

The disclosed embodiments generally relate to techniques for controlling displays in computer systems. More specifically, the disclosed embodiments relate to a system that facilitates audio playback during display sleep mode.

2. Related Art

Computer displays are often equipped with built-in speakers which enable the display to output both audio and video signals. To conserve power, these displays often enter a “sleep mode,” wherein various components within the display are powered down. However, when such a display enters sleep mode, the audio components are also powered down, which can cause an audio output, such as music, to be interrupted. This leads to an unsatisfactory user experience. Also, when a host system wants to output sound and the display is in sleep mode, the display must be powered up and may suddenly produce a bright light, which can also cause an unsatisfactory user experience. Hence, what is needed is a technique that facilitates powering down display components involved in producing a video output from the display without affecting an audio output of the display.

SUMMARY

Some of the disclosed embodiments relate to a system for managing power for a display. During operation, the system receives a video-blank command, which specifies that the display is to enter a video-blank mode wherein the display outputs a blank screen. In response to the video-blank command, the system causes the display to output a blank screen, and powers down display components associated with outputting a display signal to the display.

In some embodiments, the display additionally comprises audio components including an audio-output device, and powering down the display components involves maintaining an existing power state for the audio components, so that the audio components can continue to output an audio signal while the display components are powered down.

In some embodiments, the system is also configured to receive an audio-mute command, which specifies that the display is to enter an audio-mute mode wherein the audio components output a muted audio signal. In response to the audio-mute command, the system is configured to: cause the audio components to output the muted audio signal, and power down the audio components.

In some embodiments, the video-blank command is received along with a command to mute/un-mute an audio signal associated with the audio components.

In some embodiments, the display can be in one of the following modes: (1) a no-video-blank/no-audio-mute mode, wherein the display components are powered up and are outputting a display signal, and the audio components are powered up and are outputting an audio signal; (2) a video-blank/no-audio-mute mode, wherein the display components are powered down, and the audio components are powered up and are outputting an audio signal; (3) a no-video-blank/audio-mute mode, wherein the display components are powered up and are outputting a display signal, and the audio components are powered down; and (4) a video-blank/audio-mute mode, wherein both the display components and audio components are powered down.

In some embodiments, the display is one of: an external display which is external to a computer system; and an internal display which is internal to the computer system.

In some embodiments, the system is also configured to receive a sleep command, which specifies that the display is to enter a sleep mode wherein components in the display are powered down. In response to the sleep command, the system is configured to power down both display components and audio components.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates a computer system and a display in accordance with the disclosed embodiments.

FIG. 2 illustrates a software architecture that facilitates controlling a display in accordance with the disclosed embodiments.

FIG. 3A presents a flow chart illustrating how a command is communicated to a pluggable display-control module though a display-control abstraction in accordance with the disclosed embodiments.

FIG. 3B presents a flow chart illustrating how a command is communicated to a pluggable transport module through a transport abstraction in accordance with the disclosed embodiments.

FIG. 3C presents a flow chart illustrating how display properties are published in accordance with the disclosed embodiments.

FIG. 4A presents a flow chart illustrating how a display-setting interrupt is generated in accordance with the disclosed embodiments.

FIG. 4B presents a flow chart illustrating how a change in ambient lighting triggers a change in the brightness of a display in accordance with the disclosed embodiments.

FIG. 4C presents a flow chart illustrating how a display-setting interrupt is processed at a host system in accordance with the disclosed embodiments.

FIG. 5A presents a flow chart illustrating how the display powers down display-related components during a video-blank mode in accordance with the disclosed embodiments.

FIG. 5B presents a flow chart illustrating how the display powers down audio-related components during an audio-mute mode in accordance with the disclosed embodiments.

FIG. 5C presents a flow chart illustrating how the display powers down display-related and audio-related components during a sleep mode in accordance with the disclosed embodiments.

DETAILED DESCRIPTION

The following description is presented to enable any person skilled in the art to make and use the disclosed embodiments, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the disclosed embodiments. Thus, the disclosed embodiments are not limited to the embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein.

The data structures and code described in this detailed description are typically stored on a non-transitory computer-readable storage medium, which may be any device or medium that can store code and/or data for use by a computer system. The non-transitory computer-readable storage medium includes, but is not limited to, volatile memory, non-volatile memory, magnetic and optical storage devices such as disk drives, magnetic tape, CDs (compact discs), DVDs (digital versatile discs or digital video discs), or other media capable of storing code and/or data now known or later developed.

The methods and processes described in the detailed description section can be embodied as code and/or data, which can be stored in a non-transitory computer-readable storage medium as described above. When a computer system reads and executes the code and/or data stored on the non-transitory computer-readable storage medium, the computer system performs the methods and processes embodied as data structures and code and stored within the non-transitory computer-readable storage medium. Furthermore, the methods and processes described below can be included in hardware modules. For example, the hardware modules can include, but are not limited to, application-specific integrated circuit (ASIC) chips, field-programmable gate arrays (FPGAs), and other programmable-logic devices now known or later developed. When the hardware modules are activated, the hardware modules perform the methods and processes included within the hardware modules.

Computer System

FIG. 1 illustrates a computer system 120 and an associated display 100 in accordance with the disclosed embodiments. Computer system 120 can generally include any type of computer system or computational device, including, but not limited to, a computer system based on a microprocessor, a mainframe computer, a digital signal processor, a portable computing device, a personal organizer, a cell phone, a device controller, or a computational engine within an appliance. As illustrated in FIG. 1, computer system 120 includes a central-processing unit (CPU) 121, which can be coupled to one or more bridge chips, including north bridge 122 and south bridge 123. CPU 121 communicates with a memory subsystem 125 through north bridge 122, wherein memory subsystem 125 contains random-access memory, which can be organized as one or more levels of cache memory and a main memory. CPU 121 can also communicate with a storage device 126 through a peripheral bus 129, which is coupled to south bridge 123. Storage device 126 can include any type of non-volatile storage device that can be coupled to a computer system. This includes, but is not limited to, magnetic, optical, or magneto-optical storage devices, as well as storage devices based on flash memory and/or battery-backed up memory. CPU 121 can additionally communicate with the graphics-processing unit (GPU) 124 through north bridge 122. GPU 124 contains specialized components for processing graphics data, including a dedicated graphics processor and possibly a dedicated graphics memory.

As illustrated in FIG. 1, computer system 120 can communicate with display 100 through either a Universal Serial Bus (USB) interface 127, which is coupled to south bridge 123, or a DisplayPort interface, which is coupled to GPU 124.

Display 100 can generally include any type of output device for outputting visual (and possibly audio) information for a computer system. Display 100 can be an external display, which can be selectively attached to computer system 120 through an interface, or alternatively an internal display, which is integrated into computer system 120. Display 100 includes an interface circuit 102, which is coupled to computer system 120 through both a display port interface 132 and a USB interface 127. Interface circuit 102 directs a video signal 107 containing video data to display 105, and additionally directs an audio signal 108 containing audio data to audio output device (speaker) 106. Interface circuit 102 also communicates with a micro-controller 101, which communicates with and controls various components within display 100. More specifically, micro-controller 101 receives signals from an Ambient Light Sensor (ALS) 103, which is integrated into the display. Micro-controller 101 can also communicate with a Back-Light Controller (BLC) 104, which controls the intensity of a backlight for display 105. Note that micro-controller 101 can adjust the intensity of the backlighting for display 105 based on an ambient light level measured through ALS 103. This control process, along with other operations performed by the various components within display 100, are described in more detail below.

Software Architecture

FIG. 2 illustrates a software architecture that facilitates controlling a display in accordance with the disclosed embodiments. This software architecture includes a display-control abstraction 210 which exposes a generic display-control interface 211 to client code. Note that this client code can include any application code or system code that makes calls (or invocations) to control the display. More specifically, FIG. 2 illustrates a user interface 200, which provides controls that can be used to control various settings for a display, including a volume slider 201 and a brightness slider 202. When a user manipulates these sliders, calls (invocations) are made through generic display-control interface 211 to communicate associated changes in volume and brightness to display-control abstraction 210. Display-control abstraction 210 translates these calls (invocations) into calls (invocations) to a pluggable display-control module, such as MCCS control module 212 or XYZ control module 214, which are illustrated in FIG. 2. These pluggable display-control modules fit into a plug-in framework associated with display-control abstraction 210. This enables different control modules to be swapped in without having to modify the client code.

The pluggable display-control modules can communicate with display 100 by making calls (invocations) through a transport abstraction 220 that exposes a generic transport interface 221. Transport abstraction 220 translates calls to generic display-control interface 211 into calls to a pluggable transport module, such as a GPU SMBus module 222, a DisplayPort Configuration Data (DPCD) protocol module 223, or XYZ transport module 224 as is illustrated in FIG. 2. These pluggable transport modules fit into a plug-in framework associated with transport abstraction 220. This enables different transport modules to be swapped in without having to modify calls from the display-control modules. Note that FIG. 2 illustrates how DPCD module 223 can be used to send video and audio data 110 to display 100, and to receive interrupts 109 from display 100. Also note that some of these interrupts 109 can indicate that display settings have changed within display 100.

Display and Transport Abstractions

FIG. 3A presents a flow chart illustrating how a command is communicated to a pluggable display-control module though a display-control abstraction that exposes a generic display-control interface in accordance with the disclosed embodiments. Note that the display-control abstraction can be implemented using a display object, which resides in a system registry.

During operation, the system first receives a command to control the display through a generic display-control interface (step 302). Next, the system translates the command into a corresponding translated command for a pluggable display-control module including code that implements a standardized set of display-control commands (step 304). Finally, the system communicates the translated command through a plug-in framework to the pluggable display-control module (step 306), wherein the plug-in framework houses the pluggable display-control module and enables the generic display-control interface to communicate with the pluggable display-control module.

FIG. 3B presents a flow chart illustrating how a command is communicated to a pluggable transport module through a transport abstraction that exposes a generic transport interface in accordance with the disclosed embodiments. Note that the transport abstraction can be similarly implemented using a transport object, which resides in a system registry. During operation, the system first receives a command from a pluggable display-control module through a generic transport interface which facilitates communicating with the display (step 312). Next, the system translates the command into a corresponding translated command for a pluggable transport module including code that implements a standardized transport protocol (step 314). Finally, the system communicates the translated command through the plug-in framework to the pluggable transport module (step 316), wherein the plug-in framework houses the pluggable transport module and enables the pluggable display-control module to communicate with the pluggable transport module.

FIG. 3C presents a flow chart illustrating how display properties are published in accordance with the disclosed embodiments. First, the system determines what display properties are supported by the display (step 322). For example, the display may support: a display brightness; a display contrast; a display hue; a display saturation; an audio volume for an audio-output device associated with the display; and an audio balance between channels for the audio-output device. Next, the system publishes the supported display properties through the generic display-control interface (step 324). The generic display-control interface can, for example, represent the brightness for a display generically by specifying (1) a minimum value for brightness, (2) a maximum value for brightness, and (3) a current value for brightness.

Display-Setting-Change Interrupt

FIG. 4A presents a flow chart illustrating how a display-setting-change interrupt is generated in accordance with the disclosed embodiments. Note that some displays presently use interrupts for system-related purposes. For example, interrupts can be generated to notify the system that there is an authentication failure associated with High-bandwidth Digital Content Protection (HDCP) copy protection, or to notify the system that checksum errors are occurring because the display is receiving corrupted data packets. However, displays presently do not generate interrupts to indicate that a display setting has changed. The only thing that can be done in existing systems to keep track of display settings is to perform polling operations. For example, this can involve polling brightness buttons on a display to determine whether a user has pushed a brightness button to increase or decrease the brightness of the display. However, as mentioned above, this polling-based approach consumes power and can adversely affect system performance.

Referring back the flowchart in FIG. 4A, the system first determines at the display that the display setting has changed (step 402). For example, the brightness of the display can change in response to a change in ambient light detected by an ambient light sensor in the display. (This process is described in more detail below with reference to FIG. 4B.) Next, in response to the change, the system can send an interrupt from the display to the host system through a first interface, wherein the interrupt informs the host system that the display setting has changed (step 404). (Note that if the change in the display setting is triggered by a communication from the host system through the first interface, the interrupt is suppressed and is not sent to the host system. On the other hand, if the change in the display setting is triggered by a communication from the host system through a second interface which is different from the first interface, the interrupt is not suppressed and is sent to the host system.)

After sending the interrupt to the host system, the system receives a request from the host system to obtain values for one or more display settings including the changed display setting (step 406). In response to this request, the system sends updated values for the one or more display settings to the host system (step 408).

FIG. 4B presents a flow chart illustrating how a change in ambient lighting triggers a change in the brightness of a display in accordance with the disclosed embodiments. First, the system detects a change in ambient light through an ambient light sensor in the display (step 412). Next, in response to the change in ambient light, the system adjusts the brightness of the display (step 414). For example, if the ambient light decreases, the brightness of the display can be decreased to conserve power without adversely affecting the ability of a user to view the display. On the other hand, if the ambient light increases, the brightness of the display can be increased to enable the user to see the images on the display in the presence of the increased ambient light.

FIG. 4C presents a flow chart illustrating how a display-setting interrupt is processed at a host in accordance with the disclosed embodiments. First, the host system receives an interrupt from the display through a first interface, wherein the interrupt indicates that a display setting has changed (step 422). Next, in response to the interrupt, the host system sends a request to the display, wherein the request asks for values of one or more display settings including the changed display setting (step 424). In response to the request, the host system receives updated values for the one or more display settings from the display (step 426). Finally, the host system uses the updated value for the changed display setting to perform a display-related operation at the host system (step 428). For example, the host system can use the updated value to update a user interface associated with the display, so that the user interface is consistent with the updated value of the display setting. More specifically, if the brightness of the display has changed, the host system can use the updated brightness value to update a setting for a brightness slider in a user interface that is used to control settings for the display.

Video-Blank Mode

FIG. 5A presents a flow chart illustrating how the display powers down display-related components during a video-blank mode in accordance with the disclosed embodiments. First, the system receives a video-blank command, which specifies that the display is to enter a video-blank mode wherein the display outputs a blank screen (step 502). Next, in response to the video-blank command, the system causes the display to output a blank screen, and powers down display components associated with outputting a display signal to the display. At the same time, the system maintains power to audio components within the display, so that the audio components can continue to output an audio signal while the display components are powered down (step 504).

FIG. 5B presents a flow chart illustrating how the display powers down audio-related components during an audio-mute mode in accordance with the disclosed embodiments. First, the system receives an audio-mute command, which specifies that the display is to enter an audio-mute mode wherein the audio components output a muted audio signal (step 512). Next, in response to the audio-mute command, the system (1) causes the audio components to output the muted audio signal, and (2) powers down the audio components (step 514). In some cases, the display components can remain powered up to continue outputting a video signal while the audio components are powered down.

FIG. 5C presents a flow chart illustrating how the display powers down display-related and audio-related components during a sleep mode in accordance with the disclosed embodiments. First, the system receives a sleep command, which specifies that the display is to enter a sleep mode wherein components in the display are powered down (step 522). Next, in response to the sleep command, the system powers down both display-related components and audio-related components within the display (step 524).

The foregoing descriptions of embodiments have been presented for purposes of illustration and description only. They are not intended to be exhaustive or to limit the present description to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present description. The scope of the present description is defined by the appended claims. 

1. A method for controlling a display, comprising: receiving a video-blank command, which specifies that the display is to enter a video-blank mode wherein the display outputs a blank screen; and in response to the video-blank command, causing the display to output a blank screen, and powering down display components associated with outputting a display signal to the display.
 2. The method of claim 1, wherein the display additionally comprises audio components including an audio-output device; and wherein powering down the display components involves maintaining an existing power state for the audio components, so that the audio components can continue to output an audio signal while the display components are powered down.
 3. The method of claim 2, further comprising: receiving an audio-mute command, which specifies that the display is to enter an audio-mute mode wherein the audio components output a muted audio signal; and in response to the audio-mute command, causing the audio components to output the muted audio signal, and powering down the audio components.
 4. The method of claim 2, wherein the video-blank command is received along with a command to mute/un-mute an audio signal associated with the audio components.
 5. The method of claim 2, wherein the display can be in one of the following modes: a no-video-blank/no-audio-mute mode, wherein the display components are powered up and are outputting a display signal, and the audio components are powered up and are outputting an audio signal; a video-blank/no-audio-mute mode, wherein the display components are powered down, and the audio components are powered up and are outputting an audio signal; a no-video-blank/audio-mute mode, wherein the display components are powered up and are outputting a display signal, and the audio components are powered down; and a video-blank/audio-mute mode, wherein both the display components and audio components are powered down.
 6. The method of claim 1, wherein the display is one of: an external display which is external to a computer system; and an internal display which is internal to the computer system.
 7. The method of claim 1, further comprising: receiving a sleep command, which specifies that the display is to enter a sleep mode wherein components in the display are powered down; and in response to the sleep command, powering down display components associated with outputting the display signal to the display, and if the display includes audio components associated with outputting an audio signal, powering down the audio components.
 8. A system for controlling a display, comprising: a display controller configured to control the display; wherein the display controller is configured to receive a video-blank command, which specifies that the display is to enter a video-blank mode wherein the display outputs a blank screen; and wherein, in response to the video-blank command, the display controller is configured to, cause the display to output a blank screen, and power down display components associated with outputting a display signal to the display.
 9. The system of claim 8, wherein the display additionally comprises audio components including an audio-output device; and wherein, while powering down the display components, the display controller is configured to maintain an existing power state for the audio components, so that the audio components can continue to output an audio signal while the display components are powered down.
 10. The system of claim 9, wherein the display controller is additionally configured to receive an audio-mute command, which specifies that the display is to enter an audio-mute mode wherein the audio components output a muted audio signal; and wherein, in response to the audio-mute command, the display controller is configured to, cause the audio components to output the muted audio signal, and power down the audio components.
 11. The system of claim 9, wherein the video-blank command is received along with a command to mute/un-mute an audio signal associated with the audio components.
 12. The system of claim 9, wherein the display can be in one of the following modes: a no-video-blank/no-audio-mute mode, wherein the display components are powered up and are outputting a display signal, and the audio components are powered up and are outputting an audio signal; a video-blank/no-audio-mute mode, wherein the display components are powered down, and the audio components are powered up and are outputting an audio signal; a no-video-blank/audio-mute mode, wherein the display components are powered up and are outputting a display signal, and the audio components are powered down; and a video-blank/audio-mute mode, wherein both the display components and audio components are powered down.
 13. The system of claim 8, wherein the display is one of: an external display which is external to a computer system; and an internal display which is internal to the computer system.
 14. The system of claim 8, wherein the display controller is additionally configured to receive a sleep command, which specifies that the display is to enter a sleep mode wherein components in the display are powered down; and wherein, in response to the sleep command, the display controller is configured to, power down display components associated with outputting the display signal to the display, and if the display includes audio components associated with outputting an audio signal, power down the audio components.
 15. A non-transitory computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for controlling a display, the method comprising: receiving a video-blank command, which specifies that the display is to enter a video-blank mode wherein the display outputs a blank screen; and in response to the video-blank command, causing the display to output a blank screen, and powering down display components associated with outputting a display signal to the display.
 16. The computer-readable storage medium of claim 15, wherein the display additionally comprises audio components including an audio-output device; and wherein powering down the display components involves maintaining an existing power state for the audio components, so that the audio components can continue to output an audio signal while the display components are powered down.
 17. A computer system, comprising: a processor; a memory; a display; and a display controller configured to control the display; wherein the display controller is configured to receive a video-blank command, which specifies that the display is to enter a video-blank mode wherein the display outputs a blank screen; wherein in response to the video-blank command, the display controller is configured to, cause the display to output a blank screen, and power down display components associated with outputting a display signal to the display.
 18. The computer system of claim 17, wherein the display additionally comprises audio components including an audio-output device; and wherein, while powering down the display components, the display controller is configured to maintain an existing power state for the audio components, so that the audio components can continue to output an audio signal while the display components are powered down.
 19. The computer system of claim 17, wherein the video-blank command is received along with a command to mute/un-mute an audio signal associated with the audio components.
 20. The computer system of claim 17, wherein the display is one of: an external display which is external to a computer system; and an internal display which is internal to the computer system. 